Current leakage in SRAM varies depending on its supply voltage. In various approaches using SRAM the internal supply voltage (e.g., VDDI) for an SRAM macro is equal to the SRAM supply voltage (e.g., VDD) minus the voltage drop across a diode (e.g., voltage Vdiode). Voltage Vdiode, however, is affected by temperature (e.g., temperature T) and the current flowing through the diode (e.g., current I), in which current I and thus the leakage current increase exponentially with respect to temperature increase. Voltage Vdiode also varies depending on the technologies and the size of the transistor forming the diode, making it complicated to determine voltage Vdiode to be used in various applications. These approaches, additionally, cannot track variations in manufacturing process used to build the SRAM cell.
Like reference symbols in the various drawings indicate like elements.